Nippon Telegraph and Telephone Corporation

Kyo Minoguchi

Tomoaki Yoshida

Toshiaki Shitaba

Yoshiaki Kisaka

Seiji Okamoto

Etsushi Yamazaki

Fukutaro Hamaoka

Hiroaki Katsurai

Yoichi Fukada

A light receiving portion of a photodiode is connected to an external light source via an optical transmission line. A power storage unit stores electrical energy generated by the photodiode. A bias circuit takes out electrical energy corresponding to the amount of stored power from the power storage unit, and applies a voltage to the cathode of the photodiode.

Optical power reception apparatus, communication apparatus and optical power reception method

An optical communication system includes a first optical communication device; a plurality of second optical communication devices configured to perform communication with the first optical communication device; a chromatic dispersion compensation device connected to the first optical communication device; and an optical transmission line connected to the chromatic dispersion compensation device, a path of the optical transmission line connected to the chromatic dispersion compensation device being split into a plurality of paths at a branch point, the resulting paths being respectively connected to the plurality of second optical communication devices, and the optical transmission line being configured to transmit optical signals through the paths, in which the chromatic dispersion compensation device includes a chromatic dispersion compensator configured to perform chromatic dispersion compensation corresponding to amounts of chromatic dispersion generated in optical signals propagated through respective paths between the first optical communication device and the plurality of second optical communication devices.

Optical communication system

An optical transmission system includes a first optical communication device configured to output an optical signal, a first FBG-DCM configured to perform wavelength dispersion compensation on the optical signal output by the first optical communication device, and a second optical communication device configured to receive the optical signal wavelength-dispersion compensated by the first FBG-DCM through at first optical transmission path of an optical fiber.

Optical transmission system and optical transmission method

An optical communication system includes an optical line terminal and a plurality of optical network units connected by optical transfer paths. The optical line terminal includes a light transmitting/receiving unit and a control unit. The light transmitting/receiving unit transmits/receives an optical signal to/from the plurality of optical network units via the optical transfer paths. The control unit performs control to change a launch power of an optical signal transmitted from the light transmitting/receiving unit, such that, when, regarding at least one optical network unit, a monitoring value has changed to a value indicating deterioration, a receive power of an optical signal in each of the plurality of optical network units is lower than or equal to an upper limit value and a receive power of an optical signal in the optical network unit in which the monitoring value has changed is higher than or equal to a lower limit value.

Optical communication system, optical line termination apparatus and optical communication control method

Provided is a chromatic dispersion compensation method including: dividing a reception signal obtained by receiving an optical signal using a coherent detection scheme into a plurality of frequency bands; adjusting a timing on a time axis of the reception signal for each of the divided frequency bands; performing combination processing for combining the reception signals included in the plurality of frequency bands; performing chromatic dispersion compensation on the reception signal at any timing before or after the combination processing; selecting, before the combination processing, sections in which overlapping parts determined based on lengths of overlap parts are generated; outputting the reception signal for each of the selected sections as a division processing block; and removing the overlap parts from both ends of a processing block generated by combination of the division processing blocks in the combination processing so as to be continuous on a frequency axis.

Wavelength dispersion compensation apparatus, wavelength dispersion compensation method, and optical receiving apparatus

An optical transmission system includes an optical transmitter, an optical receiver, and a control apparatus. The control apparatus repeatedly performs an adjustment process for adjusting power of an optical signal of a frequency band to be adjusted while switching the frequency band to be adjusted between at least two frequency bands including at least a frequency band where stimulated Raman scattering occurs among frequency bands that are multiplexed in a multiplexed optical signal transmitted by the optical transmission system. In the adjustment process, when power of an optical signal of the frequency band to be adjusted transmitted from the optical transmitter has been changed, the control apparatus determines the power of the optical signal of the frequency band to be adjusted on the basis of a signal quality measured by the optical receiver that has received the optical signal.

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Musashino, Japan

Kyo Minoguchi